Topic: 1975 CB550F Carb Issues?

[dave550K]

Hey All,
I am having trouble with my 550F. The bike has been sitting for 15 years and I just finished a rebuild on the carbs.
Now it runs but not well.

All the way from idle to about 5000 RPM the bike back fires constantly.
At about 4500 - 5000 the carbs spit air and fuel out of the air filter and it loses all power.
When riding down the road( if you could call it that), it will barely accelerate with out the choke on.

Does this sound like a jet(or mixture) problem in the carbs or some other problem. I am new to the mechanics of these old bikes,
but I am very capable of adjusting with a little insight.

Thanks for any help,
Dave

[kettlesd]

I'd say its flooding badly - since you are blowing fuel out the filter, but if it only runs with the choke, it seems you are running lean. You need a complete carb tear down and tuneup. Look in the FAQ's for know-how. Be sure to clean out all the jets and airways, set the float height,timing, valve clearance, etc.

CLean out those carbs! Its the badge of honor amongst SOHC owners..........

[mb3000gt]

when you say "rebuild" what did that include? did you make sure the jets were completely clear? did you set the float height?

[kettlesd]

Yeah, my point exactly. Forgive us if we are wrong, but so many times we ahve heard "complete rebuild" and it simply has not been the case! Im sure there are some basic carbueration issure here, as i said in my last post.

[csendker]

I have electronic copies of the Keihin Rebuild Manual and the Honda Motorcycle Carburation Manual.  I can e-mail them out if you're interested.  The Keihin manual is pretty much a short step-by-step rebuild with lots of pretty pictures.  The Honda manual gets more technical but adds lots of insight.

[Fish]

'75 cb550f?  Nice!
Csendker has been a huge help to me in the past for info too.

- Chad

[dave550K]

Thanks Guys!

What I did was bought a kit off of ebay with all the new parts and installed it after a thourough cleaning. I have a clymer manual and I set the float heights according to that I think it was 25 mm or something off the top of my head. I bought a dip bucket from autozone, that actually worked really well. You can take all the pieces off and put them in there and it eats all of the build up off.

I am assuming that I have some timing, or valve clearance issues. I spent a lot of time cleaning up the insides. (They look like new inside, but not out)

I will do some reading in the FAQ and see what I can come up with thanks for the help!
I got so lucky with this bike. I got it off a guy for $75, brought it home and kicked it about thirty times and it fired right up.
Then tore it apart and painted everything. Put it back together, now I just have to make it run "right" and fix the turn signals.


Dave

[dave550K]

Oh and yes I would love those manuals.

kelandav@yahoo.com

Thanks again,
Dave

[doug_id]

Hello, if you wouldn't mind can you e-mail me the manuals as well?

Doug_id@yahoo.com

Thx!